Transcript Triangles

Classifying Triangles
Lesson 8-4
Classifying by Angle
•Acute triangles have three acute angles.
•Obtuse triangles have one obtuse angle.
•Right triangles have one right angle.
Classifying by Sides
•Equilateral triangles have three congruent
sides.
•Isosceles triangles have two congruent
sides.
•Scalene triangles have zero congruent
sides.
Finding Missing Angles
•The three angles of a triangle always add
to 180°.
•Use a variable to stand for the missing
angle and set an equation equal to 180.
x + 49 + 47 = 180
x + 96 = 180
– 96 = -96
x = 84
Homework Time!